An Indian drone has “invaded” China’s airspace and crashed, Chinese state media said on Thursday, months after the neighbors ended one of their worst border standoffs in decades.

“The Indian move violated China’s territorial sovereignty. We strongly express our dissatisfaction and opposition,” Xinhua news agency cited the deputy director of the army’s western theater combat bureau, Zhang Shuili, as saying.

Zhang did not give details about when or where the incident happened.

Chinese border troops “took a professional and responsible attitude” and carried out identification verification of the device, Zhang added.

In August, the two nations pulled back their troops to resolve a tense deadlock over part of a Himalayan plateau claimed by both China and Bhutan, an ally of India.